/*
    Copyright (C) 2016  PencilBlue, LLC

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/
'use strict';

//dependencies
var util = require('../util.js');

module.exports = function TemplateEntityService(pb) {

    /**
     * Service that is used to load the HTML templates from the file system.  If
     * the template is available it is compiled.
     *
     * @module Services
     * @class TemplateEntityService
     * @constructor
     * @param {String} startMarker The string that represents the begining of
     * directives.
     * @param {String} endMarker The string that represents the ending of
     * directives.
     */
    function TemplateEntityService(startMarker, endMarker){
        this.type        = 'Template';
        this.objType     = 'template';
        this.startMarker = startMarker;
        this.endMarker   = endMarker;
    }
    util.inherits(TemplateEntityService, pb.FSEntityService);

    /**
     * Retrieve a value from the file system.  Will callback with an object with
     * two properties.  "key" the file path.  "parts" an array of objects.
     *
     * @method get
     * @param  {String} key the file path to the template
     * @param  {Function} cb A callback function that takes two parameters: cb(Error, Object)
     */
    TemplateEntityService.prototype.get = function(key, cb){
        var self = this;
        var callback = function(err, content) {

            //log result
            if (pb.log.isSilly()) {
                pb.log.silly('TemplateEntityService: Attempted to retrieve template content.  FILE=[%s] CONTENT_LEN=[%s]', key, content ? content.length : 'n/a');
            }

            //compile the content
            var structure = null;
            if (pb.validation.isNonEmptyStr(content, true)) {
                structure = {
                    key: key,
                    parts: pb.TemplateService.compile(content, self.startMarker, self.endMarker)
                };

                if (pb.log.isSilly()) {
                    pb.log.silly('TemplateEntityService: Compiled into %d parts', structure.parts.length);
                }
            }
            cb(err, structure);
        };
        TemplateEntityService.super_.prototype.get.apply(this, [key, callback]);
    };

    /**
     * This function is not implemented.
     *
     * @method set
     * @param {String} key The absolute file path
     * @param {*} value The string content to set
     * @param {Function} cb    Callback function
     */
    TemplateEntityService.prototype.set = function(key, value, cb) {
        throw new Error('Not Supported');
    };

    return TemplateEntityService;
};